STRUCTURE.] AUTHOR^ METHOD. 21 



Coenobio: it differs from the Carcerulus in nothing but the low insertion of the 

 style into the ovaria, and the distinctness of the latter. 

 Examples. Tilia, Tropceolum, Malva. 



XIII. SAMARA, G<ertn. Key. (Pteridium, Mirb.; Pterodium, Desr.^fig. 145. 

 Two or more celled, superior; cells few-seeded, iudehiscent, dry; elongated 



into wing-like expansions. This is nothing but a modification of the Carcerule. 

 Examples. Fraxinus, Acer, Ulmus. 



XIV. PYXIDIUM. (Pyxidium, Ehr. t Rick., Mirb.', Capsula circumscissa, L.) 



fig. 154. 



One-celled, many-seeded; superior, or nearly so; dry, often of a thin tex- 

 ture; dehiscent by a transverse incision, so that when ripe the seed and their 

 placenta appear as if seated in a cup, covered with a lid. This fruit is one- 

 celled by the obliteration of the dissepiments of several carpella, as is apparent 

 from the bundles of vessels which pass from the style through the pericarpium 

 down into the receptacle. 



Example. Anagallis. 



XV. CONCEPTACULUM. (Conceptaculum, Linn.; Double Follicule, Mirb.) 



fig. 141. 



Two-celled, many-seeded, superior, separating into two portions, the seeds 

 of which do not adhere to marginal placentae, as in the folliculus, to which 

 this closely approaches, but separate from their placentae, and lie loose in the 

 cavity of each cell. 



Examples. Asclepias, Echites. 



XVI. SILIQUA, Linn. fig. 157, 158,. 159. 



One- or two-celled, many-seeded, superior, linear, dehiscent by two valves 

 separating from the replum; seeds attached to two placentae adhering to the 

 replum, and opposite to the lobes of the stigma. The dissepiment of this 

 fruit is considered a spurious one formed by the projecting placentae, which 

 sometimes do not meet in the middle; in which case the dissepiment or 

 phragma has a slit in its centre, and is said to defenestrate. 



Examples. Cheiranthus, Arabis. 



XVII. SILICULA, Linn. 



This differs from the latter in nothing but its figure, and in containing 

 fewer seeds. It is never more than four times as long as broad, and often 

 much shorter. 



Examples. Thlaspi, Lepidium, Lunaria. 



XVIII. CERATIUM. (Capsula siliquiformis, Dec.; Conceptaculum, Dew.) 

 One-celled, many-seeded, superior, linear, dehiscent by two valves separat- 

 ing from the replum; seeds attached to two spongy placentae adhering to the 

 replum, and alternate with the lobes of the stigma. Differs from the siliqua in 

 the lobes of the stigma being alternate with the placentae, not opposite. This, 

 therefore, is regular, while that is irregular, in structure. 



Examples. Glaucium, Corydalis, Hypecoum. 



XIX. CAPSULA. Capsule, fig. 146, 147, 151, 152, 136, 137. 



One- or many-celled, many-seeded, superior, dry, dehiscent by valves, always 

 proceeding from a compound ovarium. The valves are variable in their 



